The invention relates to a preparation method of indole-2-carboxylic ester, which comprises the following step: in a carbon monoxide atmosphere, carrying out a hydrocarbon carbonylation reaction in anorganic solvent with an indole derivative and alcohol as raw materials under the action of a transition metal catalyst and an oxidizing agent to obtain the indole-2-carboxylic ester compound with a general formula as the specification. The preparation method has the advantages of high atom economy, cheap and easily available raw materials, wide substrate application range, mild reaction conditions, simple synthesis process and easiness in industrialization, and can fill the defects in the prior art. The invention provides a synthetic strategy with high atom economy for the preparation of theindole-2-carboxylic ester and the derivative thereof.